<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <meta lang="zh-cn">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>运行文件库</title>
    <style>
      *, *:before, *:after {

  box-sizing: border-box;

}

html {
  margin-top: 30px;
  font-size: 18px;
  line-height: 1.5;
  font-weight: 300;
  color: #333;
  font-family: "Nunito Sans", sans-serif;
}

body {
  background: radial-gradient(ellipse at bottom, #1b2735 0%, #090a0f 100%);
  margin: 0;
  padding: 0;
  height: 100vh;
  background-color: #ecf0f9;
  background-attachment: fixed;
}

.content {
  display: flex;
  margin: 0 auto;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  max-width: 1000px;
}

.heading {
  width: 100%;
  margin-left: 1rem;
  font-weight: 900;
  font-size: 1.618rem;
  text-transform: uppercase;
  letter-spacing: .1ch;
  line-height: 1;
  padding-bottom: .5em;
  margin-bottom: 1rem;
  position: relative;
}
.heading:after {
  display: block;
  content: '';
  position: absolute;
  width: 60px;
  height: 4px;
  background: linear-gradient(135deg, #1a9be6, #1a57e6);
  bottom: 0;
}

.description {
  width: 100%;
  margin-top: 0;
  margin-left: 1rem;
  margin-bottom: 3rem;
}

.card {
  color: inherit;
  cursor: pointer;
  width: calc(33% - 2rem);
  min-width: calc(33% - 2rem);
  height: 300px;
  min-height: 400px;
  perspective: 1000px;
  margin: 1rem;
  position: relative;
}
@media screen and (max-width: 800px) {
  .card {
    width: calc(50% - 2rem);
  }
}
@media screen and (max-width: 500px) {
  .card {
    width: 100%;
  }
}

.front,
.back {
  display: flex;
  border-radius: 6px;
  background-position: center;
  background-size: cover;
  text-align: center;
  justify-content: center;
  align-items: center;
  position: absolute;
  height: 80%;
  width: 80%;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  transform-style: preserve-3d;
  transition: ease-in-out 600ms;
}

.front {
  background-size: cover;
  padding: 2rem;
  font-size: 1.618rem;
  font-weight: 600;
  color: #fff;
  overflow: hidden;
  font-family: Poppins, sans-serif;
}
.front:before {
  position: absolute;
  display: block;
  content: '';
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, #1a9be6, #1a57e6);
  opacity: .25;
  z-index: -1;
}
.card:hover .front {
  transform: rotateY(180deg);
}
.card:nth-child(even):hover .front {
  transform: rotateY(-180deg);
}

.back {
  background: #fff;
  transform: rotateY(-180deg);
  padding: 0 2em;
}
.card:hover .back {
  transform: rotateY(0deg);
}
.card:nth-child(even) .back {
  transform: rotateY(180deg);
}
.card:nth-child(even):hover .back {
  transform: rotateY(0deg);
}

.button {
  transform: translateZ(40px);
  cursor: pointer;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  font-weight: bold;
  color: #fff;
  padding: .5em 1em;
  border-radius: 100px;
  font: inherit;
  background: linear-gradient(135deg, #1a9be6, #1a57e6);
  border: none;
  position: relative;
  transform-style: preserve-3d;
  transition: 300ms ease;
}
.button:before {
  transition: 300ms ease;
  position: absolute;
  display: block;
  content: '';
  transform: translateZ(-40px);
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
  height: calc(100% - 20px);
  width: calc(100% - 20px);
  border-radius: 100px;
  left: 10px;
  top: 16px;
  box-shadow: 0 0 10px 10px rgba(26, 87, 230, 0.25);
  background-color: rgba(26, 87, 230, 0.25);
}
.button:hover {
  transform: translateZ(55px);
}
.button:hover:before {
  transform: translateZ(-55px);
}
.button:active {
  transform: translateZ(20px);
}
.button:active:before {
  transform: translateZ(-20px);
  top: 12px;
}
    </style>
</head>

<body style="color: white">
  </br> 
<strong style="font-size: 30px;margin: 25px">喜气洋洋小四班核心代码调用仓库</strong>

<strong>Bookstrap</strong>
</br>
</br>
<strong style="margin: 25px">由喜气洋洋小四班班刊开发团队开发</strong>
</br>
</br>

<div class="content">


  <a class="card" href="Core-documents/static/css/css.html">
    <div class="front" style="background-image: url(Immaterial-documents/picture/CSS.jpg);">
      <p>Cascading Style Sheets</p>
    </div>
    <div class="back">
      <div>
        <p>CSS样式代码库</p>
        <p>请在此处直接调用</p>
        <button class="button">访问</button>
      </div>
    </div></a><a class="card" href="Core-documents/static/js/js.html">
    <div class="front" style="background-image: url(Immaterial-documents/picture/JS.jpg);">
      <p>JavaScript</p>
    </div>
    <div class="back">
      <div>
        <p>JavaScript调用库</p>
        <p>请在此处直接调用</p>
        <button class="button">访问</button>
      </div>
    </div></a><a class="card" href="Core-documents/static/font/font.html">
    <div class="front" style="background-image: url(Immaterial-documents/picture/FONT.jpg);">
      <p>Font style</p>
    </div>
    <div class="back">
      <div>
        <p>字体库</p>
        <p>请在此处直接调用</p>
        <button class="button">访问</button>
      </div>
    </div></a>
</body>

</html>